Organic Nitrogen Compounds: Amides & Amines

Amides and Amines: Organic Nitrogen Compounds

• Nylon is a material used to make colorful sails due to its strength and durability
• Amides are neutral nitrogen-containing compounds
• They are neither acidic nor basic, existing as molecules in both aqueous solutions and pure form
• Amides contain carbonyl groups directly connected to a nitrogen atom
• Amides are prepared from carboxylic acids and ammonia through heating.

Amides: Nomenclature and Physical Properties

• Amides are formed when a carboxylic acid is heated in the presence of ammonia
• This process produces an ammonium salt as an intermediate
• This intermediate is further heated forming the amide and water
• Ammonium salts of carboxylic acids can also be converted to amides by heating

IUPAC Rules for Naming Amides

• The longest continuous carbon chain containing the amide group is used as the base name
• The carbonyl carbon is labeled as the #1 carbon atom
• The -oic acid suffix is dropped from the corresponding carboxylic acid and replaced with -amide

IUPAC names for amides

• IUPAC names for amides are derived from the corresponding carboxylic acid
• The -oic acid ending is replaced with -amide
• Examples include methanamide (from methanoic acid) and ethanamide (from ethanoic acid)

Additional Naming Rules for Amides

• A capital 'N' (italicized) is used as a prefix if alkyl groups or other substituents are attached directly to the amide nitrogen atom
• Examples include N-methylacetamide and N,N-diethylpropionamide

Common Names for Amides

• Common names for amides are derived from the common names of the corresponding carboxylic acids
• Examples include formamide from formic acid and butyramide from butyric acid

Physical Properties of Amides

• Amides exhibit high water solubility and high melting/boiling points, primarily due to strong intermolecular hydrogen bonding
• Low molar mass amides are soluble in water

Chemical Properties of Amides

• A crucial reaction of amides is hydrolysis, which involves breaking the amide bond using either acid or base
• Acidic hydrolysis produces a carboxylic acid and an ammonium salt
• Basic hydrolysis produces a carboxylate salt and ammonia

Polyamides: Condensation Polymers

• Polyamides are polymers containing repeating amide linkages
• Polyamides can be synthetic, like Nylon-66, or biological, such as the protein chymotrypsin
• Nylon-66 has a specific repeating structural unit

Urea

• Urea is a diamide that's naturally excreted as a nitrogenous waste product
• It's a white solid, soluble in water, and melts at 133°C
• Urea is used as a fertilizer and in plastic/barbiturate production

Classification of Amines

• Amines are nitrogen-containing organic compounds that are classified based on the number of hydrocarbon groups attached to the nitrogen atom
• These include primary, secondary, and tertiary amines

Examples of Primary, Secondary, and Tertiary Amines

• Examples of primary amines include methylamine and aniline
• Examples of secondary amines include methylaminoethane and diethylamine
• Examples of tertiary amines include triethylamine

IUPAC Rules for Naming Amines

• The longest continuous carbon chain containing the amine group is used as the base name for the amines
• The carbon atom connected to the amine group is the #1 carbon
• The suffix -e of the corresponding alkane is dropped and replaced by -amine

Naming Aliphatic Amine Derivatives

• Common names for aliphatic amines are formed by naming alkyl groups or substituents followed by the suffix -amine
• Examples such as ethylamine, propylamine, isopropyl amine, tert-butylamine, and ethyldimethylamine are found

Naming Aromatic Amines

• Aromatic amines are primarily identified by their common name, aniline (C₆H₅NH₂)
• Amine derivatives use the substituted aniline naming convention

Physical Properties of Amines

• Amines are capable of hydrogen bonding with water, which contributes to their water solubility, this is most apparent in lower-molecular-weight amines
• Flammable gases, with varying odors, can occur in primary amines.

Preparation of Amines

• Amines can be prepared through various processes
• Alkylation of ammonia, Reduction of amides, Reduction of nitriles, and Reduction of aromatic nitro compounds

Chemical Properties of Amines

• Amines exhibit alkaline properties, acting as weak bases in water, producing hydroxide ions; some are flammable gases
• A reaction of amines with strong acids forms ammonium salts
• Amides are formed through the reaction of amines with acid chlorides

Sources and Uses of Selected Amines

• Various amines are found in biological systems
• Biogenic amines often function as neurotransmitters and hormones
• Some amines are components of widely-used stimulants or medications
• Other amines are components of various products, and some can be noxious

This quiz explores the properties, nomenclature, and formation of amides and amines, organic nitrogen compounds with unique characteristics. Learn about their preparation methods from carboxylic acids and their distinct naming conventions according to IUPAC rules.